From page 2 of the how-to guide:
One of the true joys of the Credit Card program is that it has continued to evolve over the years. Although it started out in a rather simple fashion, it just kept getting better and better as I developed new components to add the original concept. Within a decade of use, it had grown into a year-long immersion into the realities of economics.
In the book Eight Great Ideas, I covered just the basics of Credit Card use: what I now call Level One. In this free teacher's guide, I'll explain how you can kick it up a notch--Level Two--with just a few modifications and enhancements. And, whenever possible, I'll point out the secrets to my success along with a few of the things I learned not to do.
Note: Although you can use the Credit Card program at any time of the year, it's a great activity/strategy/idea to use after Spring Break. It will add a new jolt of energy to each day which will benefit both you and your students. Credit Cards was always a student favorite in my classroom and I'm guessing, that become too long, it will become a regular part of your school year.